Those people who are short generally live longer than the tall ones. This could be because of a rare gene mutation that limits a particular growth factor, a new study has suggested.

And, this particular mutation has been found mostly among women.

This mutation, according to Dr Nir Barzilai, lead researcher and director of the Institute for Aging Research at the Albert Einstein College of Medicine in New York City, seems to reduce the activity of insulin-like growth factor (IGF-1), resulting in short stature but longer life.

Why exactly this might lengthen someone’s life is not yet known, but the researchers say that the finding might prove useful in developing anti-aging drugs.

In the study, published in Proceedings of the National Academy of Sciences, Dr Nir Barzilai wrote, “We found that people of a hundred years old have mutations in a gene that is related to the growth hormone pathway. We think this is important, because that’s what now happens in nature. The pony lives longer than the horse, the small dog lives longer than a large dog. Apparently, it’s true for humans also.”

Based on these findings, it might be possible to develop drugs that can prevent aging and age-related disease, Dr Barzilai added.

In the study, Dr Barzilai’s team searched for the particular gene mutation among a population of northern or eastern European Jews, or Ashkenazi Jews, who were aged between 95 and 110, as well as their offspring. They also matched these offspring with people who had no history of longevity in their family.

The researchers found that this particular mutation was more common among those who were centenarians and also their offspring.

The same research team had reported in December 2006 that a particular gene variant that is linked to longevity is also associated with improved mental function in the elderly.

Dr Barzilai said that growth hormone, which changes the tone of the skin and fat distribution and increases muscle mass, is a very popular anti-aging therapy. But, he added, “The new study as well as other studies suggest that, for the purpose of aging and longevity, growth hormone might do exactly the opposite. In the short run, growth hormones are going to have positive effects, but certainly in elderly people I would suggest, and this study supports the notion, that we will kill them sooner rather than later.”

Dr Nir Barzilai, who was born in Israel, said he decided to study Ashkenazi Jews because of their unique characteristics. “While they do not have a longer-than-normal life span, they offer very limited genetic diversity, owing to centuries of enforced isolation and oppression in Europe,” he explained in the Proceedings of the National Academy of Sciences.